Manchin has joined with Rep. Ed Whitfield, R-Ky., on a bill that would block the Obama administration's current plans to issue he first-ever limits on carbon dioxide emissions from power plants as part of broader effort to curb climate change.

On Thursday, House Republicans scheduled a hearing to promote the Manchin-Whitfield proposal and to repeat their concerns that the U.S. Environmental Protection Agency is wrongly targeting the coal industry.

Testifying before a House Energy and Commerce subcommittee, Manchin complained that EPA "is holding the coal industry to impossible standards" and that utilities are "still a ways off" from developing carbon capture and storage technology, or CCS.

But other witnesses at the hearing said that concrete rules like those proposed by EPA would actually help the coal industry, and that Manchin's plan to delay the agency would do more harm than good for mining communities.

Susan Tierney, an energy and economics consultant with the Boston-based Analysis Group, told lawmakers that the EPA rules "will help to clarify the rules of the road" for both coal and natural gas.

"Having clear rules and policy stability will help support a positive investment environment at a time when new generating capacity and investor support for billions in financing will be needed in many parts of the country," Tierney testified.

David Hawkins, director of climate programs for the Natural Resources Defense Council, said that the legislation "would not improve the lot of coal producers or communities in coal country."

"Rather, it would destroy power sector interest in deploying carbon capture and storage systems - the one technology that could provide a pathway for more sustainable use of coal," Hawkins said in his testimony.

For years, scientists have been urging major cuts in emissions of carbon dioxide and other greenhouse gases to avoid the worst impacts of rising global temperatures.

One study out this week warned that the global temperature rise of the past 15 years has been greatly underestimated. This new analysis, by British and Canadian researchers, shows the much-hyped "warming pause" disappearing.

Many experts have concluded that the key to coal's survival in a carbon-constrained world is to perfect and widely deploy equipment to capture carbon dioxide emissions from power plants and pump those gases underground.

Critics worry about the expense, safety and a host of technical hurdles, including the huge infrastructure needed to install the equipment on power plants across the world. Environmental and citizen groups also are hesitant to support CCS, worrying that the talk of "clean coal" allows the government and industry to ignore what they argue are other much-needed improvements in the regulation of how coal is mined and burned, and how coal wastes are handled.

Some coal-state political leaders once touted CCS as a reality -- as the "clean coal" that could power the future -- but now that EPA has actually proposed greenhouse gas limits, those political leaders say the agency is asking the industry to do too much too quickly.

But last month, a new report from the nonpartisan Congressional Research Service concluded that a major hurdle for CCS research and development is the lack of a market for the technology.

"While various types of incentive programs can accelerate the development and deployment of CO2 technology, actions that significantly limit emissions of CO2 to the atmosphere ultimately are needed to realize substantial and sustained reductions in the future cost of CO2 capture," the report said.

"Only if a government action either required CO2 capture and storage, or made it financially worthwhile to reduce CO2 emissions, would a sizeable market be created for technologies that enable such reductions," the report said. "As with other environmental emissions that affect public welfare, government actions are needed to create or enhance markets for CO2 emissions-reducing technologies."

Testifying at Thursday's hearing, acting EPA assistant administrator for air Janet McCabe said the Manchin-Whitfield bill would not only block important emissions limits, but also slow the development of new pollution-control technologies.

"Such a requirement would stifle progress in reducing carbon pollution by discouraging the adoption of innovative technology that is available and effective today - and would limit further development of cutting-edge clean energy technologies," McCabe testified.